BAGHDAD, Iraq (CNN) -- A group of al-Qaeda in Iraq prisoners overpowered a police officer before killing him and other officers in a jailbreak in Ramadi early Friday, Interior Ministry officials said.

Seven of the militants were killed in a gunbattle with police outside the al-Fursan police station shortly after their escape, but three others managed to get away, the officials said.

It is not yet known what happened to the other prisoner.

The jailbreak began when a prisoner asked a police officer to escort him to the toilet at about 1 a.m., the officials said. The other 10 prisoners in the cell pretended to be asleep when the officer entered, but they attacked him and took his gun, officials said.

After shooting the first police officer, the prisoners used his gun to kill five other police officers on their way out of the police station. The dead included two high-ranking officers, according to officials.

The al-Fursan police station is located in the Anbar province about 100 miles west of Baghdad.

An Iraqi police officer was also killed Friday in Anbar province when a truck driver opened fire on an Iraqi police checkpoint in Falluja, an Interior Ministry official said.

The truck driver was killed in an exchange of gunfire, the official said. Police later learned the truck was rigged with explosives.

Much of Anbar province was once controlled by al-Qaeda in Iraq, but the local Awakening Councils, which are supported by Iraqi security forces, now dominate.

U.S. troops handed over the security control of Anbar province to Iraqi security forces on September 1, 2008.